Grab



RAB

Filed Nov. 192.4

M HID n maoE N EJQ ATTORNEY INV Patented July 21, 1925.

P EN OFFICE.

CHARLES MCCARTHY, 0F LONG BEACH, CALIFORNIA.

1 GRAB.

To all'whom itmayooncernr v Be it known that 1, CHARLES S. Mo-

C RrrIY, a citizen of the United States, and

a resident of Long Beach, in the county oi. Los Angeles and State of California, have invented certain new and useful Improvea specification.

This invention relates generally to a releasable lifting grab, and particularly to means for unseating the standing valve in an oil well pump.

. It is one o bject of the invention to provide a grab of the character indicated that may be thrown into and out of engagement with a standing valve without unscrewing [the sucker rod while i, disengaging the grab from the' valvew i It is another object of theinventionto obviate the necessity of using a, garbut rod for unseating the standing valve in an oil ments in Grabs, of which the following is o well pump whereby a valve may be provided in the lower end of the pump plunger.

It is another object of the-invention to provide a grab of the character indicated that will permit the withdrawal of the plunger from thewell without withdrawing the standing valve.

Still another object 0'1 the-invention-is to provide a grab that will not break under repeated heavy blows,that is automatic and positive in action, that is operated entirely by vertical movements of the sucker rod, and onethat cannot be accidentally. disengaged fromithestanding valve by sudden discharges of gas pockets.

In the drawing Figure 1 is a horizontal cross-section through the structure on line 1-1 of Figure 2. i e s Figure 2 is a section on line 22 of are 1, partly in elevation.

Figures 3,4, 5 and 6 are views corresponding to one-half of Figure 2 showing suc- Figcessive positions of the standing valve liftring and replacing element.

Referring moreparticularly to the drawing, 1 show at 1 a portion of the upper end of the standing valve cage into which is screwed a pin 3. as at2. i v

This pin 3 has a reduced portion at l'to engage a collar 5, this collar 5 being removable and having an outside diameter somewhat larger than pin 3 as shown, and

Application filed November 29, 1924. Serial No. 752,983.

held in place by engagement with the shoulder 6 on pin and cage 1 as shown.

A little above shoulder 6 an annular groove 7 is formed in pin 3as shown at 7, this groove supporting a compression spr1ng8. v

A distance above groove 8 is formed an annular flange 9 tollowedby a groove 10 in which is placed a compression spring 11.

.At 12 I show a sleeve mounted to slide on pin 8, between flange 9 and spring 8, and havingits lower inner edge bevelled as at 13 so thatwhen su'flicie'nt pressure is applied thereto from above the sleeve will compress spring8 into groove 7 and slide downwardly thereover until it contact-S with the upper edge of collar 5.

Sleeve 12 has an annularv groove 14 formed thereinin whichis arranged a compression spring 15. The upper portion of sleeve 12 tapers inwardly as at 16 to a neck portion 7 and then flares outwardly toit's upper edge as at 18.

The tubular element 19 is carried by the lower end of the pump plunger in any suitable manner such as screwing on to the lower threaded end of the bottonr plunger nut 20. The, lower inner surface of element 19 converges somewhat as at 21 and forms a shoulder 22 to receive the end of a nut 23. This nut 23 has its upper inner surface bevelledas at 2 1 so as to be continuous with surface 21 when the nut is in position, and it has a comparatively sharp as at 25. i

In thebevelled surface 21 of element 19 are formed three spaced recesses 26 in which are set leaf springs 27, these springs being securedin any suitable manner-as by screws '28. The springs 27 extend upwardly a distance as shown, and normally converge at their upper ends so asto contact with pin 3 when the element 19 is dropped thereover. Referringto the springs 11, 15 and 8, they are preferably made in widely varying degrees of resiliency, their compressibilitybe ing-ro'ughly by way of example, as 4 to 2 to 1, Obviously, the ease with which these springs are compressedby a circular element moving parallel with the axis of pin 3 and engaging them throughout their circumferences, depends largely upon the form of the engaging surfaces and the force ap plied. Since the springs 11 and 15 are desired to strongly resist compression from above they are provided with well rounded upper shoulders as 29 and 30 respectively. But since they are desired to compress under much less force from below they are provided with flattened lower shoulders as 3 and 32 respectively.

Since the element 19 and nut 23 actuate these springs, the bevel 25 on nut 23 is made somewhat flat to cooperate with shoulders 29 and 30 on springs 11 and 15, and bevel 21*% is more gradual to cooperate with shoulders 31 and 32 on springs 11 and 15.

Suppose, now, it is desired to lift the standing valve to permit the draining of the well and to replace the same after said draining andprior to pulling the pump from the well.

The plunger is dropped a distance, the bevel 25 on nut 23 engaging shoulder 29 on spring 11. The spring 11 absorbs the initial shock of the blow but is compressed thereby and the plunger descends until the bevel 25 engages shoulder 30 on spring 15. This engagement causes the sleeve 12 to slide downwardly on pin 3 until its bevelled surface 13 engages spring 8. This still further breaks the force of the blow, but since spring 8 is weaker than spring 15 the sleeve 12 compresses it and passes thereover until it is seated upon the upper edge of collar 5. The descending plunger now compresses spring 15 and passes thereover until it seats upon the cage 1 as shown in Figure 3, the springs 27 assuming the position shown.

To unseat the standing valve the cage 1 is now lifted by drawing up the plunger, the bevel 24 on nut 23 first engaging shoulder 32 on spring 15 and moving the sleeve 12 upwardly until clear of spring 8, the springs 27 engaging the under side of flange 9 and lifting the cage as described and as shown in Figure 1.

The draining being completed, the plunger is again dropped until it rests upon cage 1, but since the sleeve is supported on spring 8 the springs 27 are carried down over the upper edge of sleeve 12 to seat in the neck portion 17 thereof, when the upward movement of the plunger again occurs as shown in Figure 5.

As the plunger moves upwardly the springs 27 carry the sleeve 12 upwardly until it engages flange 9, but since this end of the sleeve is flared at 18 further pulling of the plunger causes the springs 27 to open up or spread and slide over part 18, flange 9, and spring 11, the bevel 24 on nut- 23 like- "wise engaging shoulders 32 and 31 on springs 15 and 11 and compressing them sufficiently to pass thereover without lifting the cage 1.

From the foregoing it may be seen that the blow of the dropping plunger is absorbed by the several springs as it travels down to cage 1, thereby practically eliminating the possibility of breakage, and no turning or twisting of the same is required to secure the desired engagement with the pin 3. Upon raising the standing valve cage by pulling up the plunger a distance the sleeve 12 is set to receive springs 27. Upon lowering the plunger to again lower cage 1 the springs 27 are placed in engagement with sleeve 12 so that upon the final raising of the plunger it is entirely disengaged from the valve cage 1 and parts carried thereby, again without turning or twisting or other manipulation.

It is to be understood, of course, that while I have herein shown and described one specific embodiment of the invention, changes in form, construction and method of operation may be made within the scope of the appended claims.

I claim 1. A grab comprising a pin, a sleeve slidably mounted thereon, a compressible spring ar anged in the pin to limit the sleeve movement undera predetermined pressure, a compressible spring positioned in said sleeve, a compressible spring positioned in said pin above said sleeve, and a grab element adapted to compress and pass over said spring and means carried by said element adapted to engage said pin for lifting the same.

2. A grab comprising a pin, and a gravity actuated grab element adapted to pass thereover, a sleeve slidably mounted thereon, resilient means for resisting the movement of the sleeve forwardly on the pin, resilient means for resisting the movement of the grab element over the sleeve, resilient means for resisting the movement of the grab element over the pin prior to its passage over the sleeve, and means carried by the grab element adapted to engage said pin for lifting the same after the sleeve has passed over the resilient resisting means obstructing its forward movement.

3. A grab element comprising a pin and a gravity actuated grab element adapted to pass thereover, a sleeve slidably mounted thereon, stops for positively limiting the sleeve movement in either direction, resilient means inserted between the sleeve and pin for resisting the movement of the sleeve over said pin, resilient means carried by the pin to receive the impact of the grab element, resilient means carried by the sleeve and positioned in the path of travel of the grab element to resist its passage thereover, and fingers carried by said grab element adapted to engage the pin for lifting the same when the said grab element has passed over said sleeve.

1. A grab element comprising a pin having upper and lower spaced compression over, and engage the sleeve ring whereby to force said sleeve over the supporting lower ring to engage the lower stop, and. 10 resilient fingers carried by said grab element adapted to engage the upper stop on said pin for lifting the same.

CHARLES S. MCCARTHY. 

